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A major technological challenge for human race in 21 st century is the transition from fossil-fuel-based energy economy to renewable (sustainable) energy one. Collective energy demand of the planet is predicted to be doubled by the mid of 21st century and to be tripled by the end of this century. There is a urgent need to develop CO 2 - neutral energy sources. The sustainable energy alternatives should be cost effective. Sustainable Energy: Need a Major Breakthrough

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The melting point of gold particles decreases dramatically as the particle size gets below 5 nm For nanoparticles embedded in a matrix, melting point may be lower or higher, depending on the strength of the interaction between the particle and matrix.

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Benefits already observed from the design of nanotechnology based products for renewable energy are: An increased efficiency of lighting and heating Increased electrical storage capacity. A decrease in the amount of pollution from the use of energy

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Portfolio of solar/thermal/electrochemical energy conversion, storage, and conservation technologies, and their interactions Workshop on Nanotechnologies for Thermal and Solar Energy Conversion and Storage, August 10,11, 2008, Jacksonville, FL Opportunities of Nanoparticles for Energy and Environment

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Electricity generation accounts for about 37% of primary energy consumption in the U.S. Lighting accounts for 22% of the nation’s electric power usage. The DoE SSL Goal: a solid-state lamp that is more efficient, longer lasting and cost competitive compared to conventional technologies, targeting a system efficiency of 50% and the color quality of sunlight. Implications of Success: 33% reduction in energy consumed for lighting by 2025, eliminating need for 41 1000MW power plants, and saving consumers $128 B+.

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Problem: Fast energy loss by hot carriers – Hot carriers are produced when solar photons with energy significantly higher than the band gap of the semiconductor is absorbed. Excess energy leads to lattice vibrations and thus affects the efficiency. Solution 1: Use of Si nanocrystals with different band gap values to capture the full solar spectrum Solution 2: Use of quantum confined nanocrystals to generate multi-exciton generation

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Organic dye sensitized solar cells Charge-carrier recombination problem can be addressed by using nanoparticle /nanostructures. Carrier collection efficiency can be improved by using one dimensional nanostructures such as nanowires and nanotubes. Nanotechnology may provide routes for cost reduction by using thin films.

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Hydrogen from solar water splitting Photoreduction of CO 2 with water to form hydrocarbon (methane, methanol etc.) – This approach is very interesting as using CO 2 as a raw material to produce hydrocarbon fuels just by using sun light. – Negative CO 2 foot print – Not only interesting from the environment point of view, but also from the view of sustainable transportation using the existing Infra structure for fuel distribution

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TiO2 nanoparticles are used in solar water splitting Increasing the efficiency of the process is a main challenge Oxynitride of TiO2 (TiO2-xNx) is a better alternative Nanosized TiO2-xNx can absorb in the visible region Solar Photocatalysis

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Despite the huge advantages, their commercialization is hampered by: – High cost – Durability issues – Operability issues Solutions for some these bottlenecks will be from nanotechnology e.g.: Replacing Pt catalysts with some cheaper material in low temperature fuel cells Fuel Cells

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What is the problem? Hydrogen fuel cell development has some practical issues associated with cost benefit and infrastructure development for safety and economics (e.g., fuel manufacturing, transportation, and storage). Although hydrogen has a high energy density by weight, it has a low energy density by volume as compared to hydrocarbon-based fuel cells. Thus, hydrogen storage is one of the bottlenecks for hydrogen fuel cell development since high-pressure compressed gas tanks are large and heavy. In addition, compressing hydrogen to high pressures require energy as well, defeating some of the cost benefits with fuel cells. Liquid hydrogen storage, which does not have a great energy density by volume as compared to hydrocarbon, also requires cryogenic storage – a bulky and expensive option.

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a) Hydrogen production and storage by renewable resource, (b) hydrogen storage in metal doped carbon nanotubes, (c) storage in mesoporous zeolite: by controlling the ratio of different alkali metal ions (yellow and green balls), it is possible to tailor the pressure and temperature at which hydrogen is released from the material, (d) hydrogen storage in metal–organic framework (MOF)-74 resembles a series of tightly packed straws comprised mostly of carbon atoms (white balls) with columns of zinc ions (blue balls) running down the walls. Heavy hydrogen molecules (green balls) adsorbed in MOF-74 pack into the tubes more densely than they would in solid form. Hydrogen storage in tanks presently used in hydrogen-powered vehicles

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Hydrgen gas (red) adsorbed in an array of carbon nanotubes (grey). The hydrogen inside the nanotubes and in the interstitial channels is at a much higher density than that of the bulk gas

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The growth of large-area graphane-like film by RF plasma beam deposition in high vacuum conditions. Reactive neutral beams of methyl radicals and atomic hydrogen effused from the discharged zone and impinged on the Cu/Ti-coated SiO 2 /Si samples placed remotely. A substrate heating temperature of 650 °C was applied http://www.intechopen.com/books/hydrogen-storage/hydrogen-storage-for-energy-application

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a) STM images of graphane. The bright protrusions in the image are identiﬁed as atomic hydrogen clusters; (b) after annealing at 300 °C for 20 min; (c) after annealing at 400 °C for 20 min; (d) graphene recovered from graphene after annealing to 600 °C for 20 min. Scale bar 3 nm

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Nanotech Materials for Truly Sustainable Construction  60% of global industrial waste is from the construction and demolition of buildings  60% of electrical use in developed nations is by buildings  40% of total energy consumed is by buildings

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 Nanogel used across North America & nine European countries  Not an experiment!  Cabot is 125 years old, a $2.9 billion public company - 21 countries - 36 manufacturing sites - 8 R&D facilities More about Aerogels

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Application : a 25mm thick multi-wall polycarbonate sheets façade filled with nano-material (Total surface of 1450m2) on the whole perimeter of the building (surface of 3360m2). The façade had to meet a thermal insulation value < 2.7 W/m.K The nano-material allows to achieve a value of 0.89 W/m.K Applications

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Shaders were not an option : very costly, heavy structure, not in line with the architect’s concept of a smooth building surface Shaders Options

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Natural daylight evenly dispersed inside the building No glare, no shadow, no “light tunnel” issues High comfort level for the players and spectators Natural daylight evenly dispersed inside the building No glare, no shadow, no “light tunnel” issues High comfort level for the players and spectators Results

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A new way of thinking  Photocatalytic cement with TiO 2  Self cleaning  Removes pollutants in area around building (CO 2, NO 2, etc.)

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What is Nanogel? Aerogel resists the transfer of heat, making it a great insulator.

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Ozone Layer Depletions In the 70s it was discovered at the University of California Actually, it is not a hole but a decrease of the ozone layer’s thickness In the equatorial regions where the ozone layer always has been thinner, this decrease is more obvious.

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The ozone hole grows and decreases every year with the stations, disappearing slowly as the south hemisphere reaches the maximum of his summer. Climatic Factors temperature Rainfalls The Problem

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Why is The Ozone Hole Continue to GROW UP Since Montreal Protocol (1987) Small groups of the Chemical Industry, knowing that refrigerants will be banned, started to produce more. So, from 1990 to 1995 it was produced more since refrigeration with CFC’s started. CFC’s substances take a long time (10-15 years) to reach the ozone layer’s level

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CFC’s (Freons) were invented in the 30s. The most commons are CFCl3 (freon 11), CF2Cl2 (freon 12), C2F3Cl3 (freon113) y C2F4Cl4 (freon 114). DESTRUCTION PROCESS Release chlorine of certain stable compounds, which is attacked by the intense UV radiation, can strip of an atom to the ozone molecule giving rise to ClO and normal oxygen. Each molecule of CFC destroys thousand and thousand of ozone molecules. As they are not very reactives, CFC’s spread slowly (it takes years) towards the stratosphere without undergo changes; there they decompose because of the UV radiation of λ=175-220nm

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Despite the fact that the growth-rate of ozone depletion potential (ODP) in the atmosphere is starting to drop, without Molecular Nanotechnology (MNT) the impact of ozone-depleting substances (ODS) on stratospheric ozone will continue. ODS refrigerants can be replaced with MNT → The growth-rate of ODP in the ODS reservoir will become zero. Drexler proposed using sodium-containing balloon type nanobots

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The nanobots, powered by nano-solar cells, collect CFC’s and separate out the chlorine in the stratosphere. Combining this with sodium makes sodium chloride. When the sodium is gone, the balloon collapses and falls. Finally, a grain of salt and a biodegradable speck fall to Earth. The stratospheric CFC is quickly removed. There can be used also nanobots containing otherbmetals (Ca, Mg) to remove stratospheric CFC. Among ODS, halogens other than chlorine (Br) could be neutralized using this tecnique.

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“Because of nanotechnology, we will see more change in our civilization in the next thirty years than we did during all of the 20 th century” - M. Roco, National Science Foundation The future of is here now